It is a worldwide trend to broadcast television programs by transmitting digital television signals. No matter which digital television broadcast standard is used, such as Digital Video Broadcasting-Terrestrial (DVB-T) or Advanced Television Systems Committee (ATSC), it is necessary to use an antenna capable of receiving both very high frequency (VHF) radio waves and ultra high frequency (UHF) radio waves in order to receive the digital television signals.
Taiwanese Utility Model Patent No. M496247 discloses a conventional flat antenna for receiving digital television signals. The conventional flat antenna includes a pair of main radiating bodies formed with feed-in apertures, and an auxiliary radiating body connected between the pair of main radiating bodies. Each of the main radiating bodies has a substantially triangular shape. The main radiating bodies cooperatively serve as a bow-tie antenna having a broad frequency range, while the auxiliary radiating body makes the conventional flat antenna further operate as a folded dipole antenna so as to increase the bandwidth and to improve impedance matching.
However, the conventional flat antenna has relatively poor antenna gain in the VHF range, affecting image quality of the television programs. In addition, the conventional flat antenna has loop current thereon due to the configuration of the folded dipole antenna, and any conductor near the conventional flat antenna may influence distribution of the loop current. Therefore, positioning of a coaxial cable can greatly affect performance of the conventional flat antenna.